Door lock for elevators



1. T. SCHLESINGER.

DooR LocK FOR ELEvAoRs.

FILED JAN.171921.

` INVENTOR Z1 @Q71 e1/.ringer BY I ATTORNEY l Patented Mar., 6, 1923.

JOSEPH T. SCHLESINGER, OF NEW YORK, NQ Y., ASSIG-NOR. TO UTILITY v.APPI'IANCE CORPORATION, A CORPORATION OF DELAWARE.

DOOR LOCK FOR ELEVATORS.

To all zo hom it may concern Be it known that I, JosEPH T. SCHLES- rNGnP., a citizen of Hungary, and a resident 0f the city of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Door Locks for Elevators, of which the following is a specication.

The present invention relates to improvements in door-locks for elevators, and more particularly to a door-lock controlling, by the position of the door, the elevator motoi mechanism.

The main object of the invention is to provide a simple and eliicient door-actuated control mechanism for elevators, involving electric features.

Another object of the invention is to produce a simple and inexpensive door lock for elevators, including a stationary element on the door frame and a sliding element on the door, said stationary and sliding elements constituting a switch inserted in the control circuit of the motor,so that the elevator cannot be started unless the door is in its fully closed and locked position.

Another object of the invention is toy produce a door lock of the type mentioned., which is applicable both to swinging and sliding doors.

With these and other objects in view, which will more fully appear as the nature of the invention is better understood, the same consists in the combination, arrangement and construction of parts hereinafter described, pointed out in the appended claims and illustrated in the accompanying drawings, it being understood that many changes may be made in the size and proper-- tion of the several parts and details of construction within the scope of the appended claims, without departing from the spirit or sacrificing any of the advantages of theinvention.

One of the many possible embodiments of the invention is illustrated in the accompanying drawings, in which:-

Figure 1 is a front elevation, partly in section, of a door-lock constructed in accordance with the present invention; Fig. 2 is a side elevation thereof; and Fig. 3 is a front elevation of a portion of amodilied construction.

Referring now first to Figs. 1 and 2 of the drawings, the numeral 10 indicates a casing of any suitable construction and adapted to be fastened to the door frame ofan elevator, for instance by 'screws passing through lugs 11 thereon. This casing is provided with a detachable front plate 12, notshown in Fig. 1 of the drawings. In the bottom 13 ofthe casing is formed an opening 111, through which the locking bolt, carried by the elevator door,.may be projectedintothe casing. The bottom 13 includes two slanting portions 15, which converge toward the opening 14:, for a purpose hereinafter to ,be described. From the back plate16 of the casing extends outwards a projection 17, having an inclined face l8slantingtoward the sald opening. The purpose of this ar rangement will appear hereinafter. y

Within the casing are mounted two` insulating blocks 19, one on each side of the opening 141, and to these blocks are fastened, for instance by screws 20, metallic contact plates 21, forming part of a switch. The Contact plates are, preferably, made in the form of blade-springs, extending'substantially vertically, their lower ends being free and in operative relation to the opening 14 in the casing bottom. The contact plates arek inserted into the motor control circuit of the elevator, the conductors leading to the screws 20, in contact with the plates 21.

On the elevator door is mounted a vertically extending'lockingslide bar` 22, movable in guides 23, the latter being securely fastened to the door. The slide bar is provided with an operating handle 24, prefy erably hollow and containing a spring I25, bearing against the handle and against a liXed stop- 26 on the door. Thisstop eX- tends into the handle, thus acting asan additional guide for the slide bar. The spring has a tendency to project the slide bar through the opening 14 of the casing 10, its upward movement being limited by a washer 27 on said bar and abuttin against the underface of one of the guides 23. The slide bar 22 is, preferably, tubular and carries at its upper endy a head 28, on which is mounted an insulating block 29, fitting the opening 14 in the casing bottom. On this block is mounted a metallic' plug 30, adapted to be inserted between the contact plates 21. The plug is provided with an anti-friction ball 31, adapted to co-operate with the slanting portions 15 or the inclined face 18 of the projection 17, as the case may be.

The operation ot this device is as follows: lvVhen the elevator door is in its closed position, the slide bar 22 projects intol the casing 10, its plug 80 bridging the gap between the contact plates 21 and thereby completing the motor control circuit. 'Ihe insulating block 29 is projected by the spring 25 into the casing, holding the door in `locked position. The slide barv has thus a two-fold unction, to wit: It, lirst, serves as a locking bolt and, second, it performs the function of a switch plug, that is to say it constitutes the movable element ot a switch. Assuming that the elevator door is of the sliding type and moves in the direction of the arrow marked X in Fig. 1 ot the drawings toward opening position, it is obvious that, in order to open the door, iirst the slide bar must be shifted downwards in the` direction of its longitudinal aXis until it is completely disengaged from the casing 10, whereafter the door may be moved in the direction oi' the arrow mentioned. lVhen the bar is thus retracted from the casing, the motor control circuit is opened and the elevator cannot be started until the door is again closed and securely locked. In shitting the door toward closing position, the anti-friction ball 31 is brought into contact with one oi' the slanting bottom portions 15 of the casing, which acts thus as a striker, the spring 25 being thereby compressed, shifting the slide bar upwards as soon as it is brought into alignment with the opening 14 in the casing bottom,where by the motor control circuit is completed. It the door is movable in a direction opposite to the arrow X, the opposite slant-ing portion 15 of the casing bottom will act as a striker, and, if the door is a swinging one, the projection 17 will perform this function.

The modification shown in Fig. 3 ot the drawings differs from the one above. de scribed in that an anti-friction roller 82 is mounted upon the insulating block 29, in stead of the ball 31 above referred to.

What I claim is 1. In a door lock for elevators, the combination with a casing having an opening in its bottom mounted upon the door frame, of a locking slide bar on the elevator door, means for projecting said bar through said opening into said casing, spaced apart con tact plates within said casing in the motor control circuit oli' the elevator, and a metallic plug carried by said slide bar for bridging the gap between said contact plates.

2. In a door lock for elevators, the combination with a casing having an opening in its bottom mounted upon the door iframe, of a locking slide bar on the elevator door, means tor projecting said bar through said opening into said casing, and a switch in the motor control circuit of the elevator, part of said switch being carried by said casing and part by said locking bar.

3. A door lock for elevators according to claim l, comprising a Striker on said casing, and anti-friction means co-operating with said striker mounted upon said slide bar.

4:. A door lock for elevators according to claim 2, comprising a striker on said casing, and anti-friction means co-operating 'with said striker mounted upon said slide bar.

5. In a door lock for elevators according to claim l, said slide bar including` a hollow handle portion and said projectingm-eans being mounted within said handle portion.

6. In a door lock according to claim 2, said slide bar including a hollow handle portion and said projecting means being mounted within said handle portion.

7. A. door lock according to claim 1, comprising co-acting means on the elevator door and said slide bar for limiting the extent ot projection oit said slide bar into said casing.

8. A door lock according to claim 2, comprising co-actingl means on the elevator door and said slide bar for limiting the extent of projection of said slide bar into said casing.

Signed at New York, in the county of New York and State of New York, this 31st day of December, A. D. 1920.

JOSEPH T. SCHLESINGER. 

